"It's hard to define what is so incredible about this,” said Jodi Zwiebach, longtime friend of Cycle for Survival founders Jennifer Goodman Linn and her husband David Linn. "Just imagine moving all the equipment out of the gym and there are 100 or 200 bikes in the gym and everyone is doing the same thing for the same reason and everyone's been touched by this crazy disease and they're all trying to figure out a way to get rid of it.”

Cycle for Survival, founded in 2007 to raise money to fight rare cancers, will take place for the third time this Saturday, Feb. 2 from 8 a.m. through 5 p.m. at Equinox Pine Street in San Francisco.

The event became an official Memorial Sloan-Kettering Cancer Center event in 2009. The program directly funds clinical trials run by MSKCC, the world's oldest and largest private cancer center.

Equinox is the founding partner of Cycle for Survival. With its help, the program has grown from one ride in New York City in 2007 to 10 markets across the country.

"Jen used to work out at Equinox in New York City. Then when they [got] a nonprofit status, they partnered with Equinox and expanded to other states and it's truly a Sloan-Kettering and Equinox partnership,” Zwiebach said.

According to the National Institutes of Health, a "rare cancer” is one with a prevalence of fewer than 200,000 affected individuals in the United States. Rare cancers include brain, pancreatic, cervical, sarcoma, stomach, pediatric cancers and many others.

"With the support from Cycle for Survival, we are making real progress in rare cancer research,” said Dr. Gary Schwartz, chief of the Melanoma and Sarcoma Service at Memorial Sloan-Kettering. "This past year at the Annual Society of Clinical Oncology Meeting, Memorial Sloan-Kettering presented positive results from three studies partially funded by Cycle for Survival, and we are advancing these and multiple other studies on rare cancers into the next phases of clinical discovery.”

"What they (the Linns) really did was bring to the common person's attention how frequent someone has a rare cancer,” Zwiebach said.

Memorial Sloan-Kettering Cycle for Survival events will be held at Equinox locations nationwide. According to Zwiebach, teams may register up to eight riders per bike.

"It's a different kind of event,” Zwiebach said, "because you don't have to train for it.”

David Dobrow, a spin instructor at Equinox in San Mateo and Palo Alto, will teach the day of the event. Dobrow has lost multiple family members to cancer.

"I'm on a mission to see if we can raise enough money to find a cure one day,” he said. "So nobody else has to go through what I go through.”

Dobrow will captain four bikes this weekend, two in the morning session and two in the afternoon. To date, his team has raised $15,000.

"The day itself is very emotionally charged. You've got not just 100 or 200 people riding at one hour but you have all the other people watching or passing. So at one time you have 300 or 400 people in the room.”

"Every year, it nearly doubles in size and dollars raised, and we can only hope that will continue. Cycle for Survival has ignited a spirit of hope and action among the rare cancer community to join the fight to find a cure through research led by Memorial Sloan-Kettering Cancer Center along with founding partner, Equinox. This is particularly true in San Francisco where two years ago the event didn't exist, and now it's one of the leading sites nationwide,” said Courtney Caccia, Cycle for Survival (San Francisco) participant.

Jennifer Goodman Linn died in 2011 but her memory lives on through Cycle for Survival and all those participating to find a cure for rare cancers.

"Whether or not cancer has touched you, doing something like this, sweat and tears with all these people you don't know in this tiny space all at the same time is totally motivating and I just think it's a great experience,” Zwiebach said.

For more information on Cycle for Survival visit www.cycleforsurvival.org.